Or, depending on how the legislation winds up developing, they could be banned from some towns altogether.

British residents who drive diesel-powered cars could soon be docked more than $20 per day in towns and cities across the United Kingdom, as part of a series of measures designed to improve air quality in some of the nation's most-polluted municipalities.

The measure, which has been described as a "toxins tax," is expected to be unveiled by U.K. environmental minister Andrea Leadsom this week, according to British media.

The plan reportedly is considering penalties of up to £20 per day (roughly $25 at current exchange rates) for all diesel drivers—if not an outright diesel ban—in nine of the U.K.'s most polluted cities. 25 other towns would also reportedly place similar penalties on diesel-powered commercial vehicles, such as trucks and taxis, according to Auto Express.